In recent years, increased awareness of the potential interactions between rising atmospheric
CO2
concentrations (
CO2
) and temperature has illustrated the importance of multifactorial ecosystem ...manipulation experiments for validating Earth System models. To address the urgent need for increased understanding of responses in multifactorial experiments, this article synthesizes how ecosystem productivity and soil processes respond to combined warming and
CO2
manipulation, and compares it with those obtained in single factor
CO2
and temperature manipulation experiments. Across all combined elevated
CO2
and warming experiments, biomass production and soil respiration were typically enhanced. Responses to the combined treatment were more similar to those in the
CO2
‐only treatment than to those in the warming‐only treatment. In contrast to warming‐only experiments, both the combined and the
CO2
‐only treatments elicited larger stimulation of fine root biomass than of aboveground biomass, consistently stimulated soil respiration, and decreased foliar nitrogen (N) concentration. Nonetheless, mineral N availability declined less in the combined treatment than in the
CO2
‐only treatment, possibly due to the warming‐induced acceleration of decomposition, implying that progressive nitrogen limitation (PNL) may not occur as commonly as anticipated from single factor
CO2
treatment studies. Responses of total plant biomass, especially of aboveground biomass, revealed antagonistic interactions between elevated
CO2
and warming, i.e. the response to the combined treatment was usually less‐than‐additive. This implies that productivity projections might be overestimated when models are parameterized based on single factor responses. Our results highlight the need for more (and especially more long‐term) multifactor manipulation experiments. Because single factor
CO2
responses often dominated over warming responses in the combined treatments, our results also suggest that projected responses to future global warming in Earth System models should not be parameterized using single factor warming experiments.
Tropical forests are intimately linked to atmospheric CO2 levels through their significant capacity for uptake and storage of carbon (C) in biomass and soils. Increasing pressure of deforestation and ...forest degradation is begging the question as to what extent land use changes will affect C storage and release in tropical areas. Hitherto, many research efforts focused on aboveground C stocks in lowland tropical forests, but a considerable amount of C is stored in tropical soils as well. Some previous studies suggested that soil C storage increases with increasing altitude, while others found no relation with altitude. In this study, we addressed this controversy by quantifying soil organic C (SOC) stocks along an altitudinal gradient spanning a 3000m altitude difference. In addition, we sampled soils in anthropogenic grasslands in proximity to forests at different altitudes to provide information on effects of land use change. Soil was sampled on 92 forest locations down to 100cm depth in forest plots, and down to 30cm in 13 grassland plots. We found that forest SOC stocks varied predictably with altitude in our study area, ranging between 4.8 and 19.4kgCm−2 and increasing by 5.1kgCm−2 per 1000m increase in altitude. Soil properties (pH, bulk density, depth) and soil forming processes played an important role in this relationship with altitude. SOC stocks were not significantly different between forests and grasslands along the gradient in our study, due to a higher soil density in grasslands. When grassland SOC stocks were corrected for this difference in soil density, forest soils contained a significantly greater amount of C. In addition, while this difference was negligible at low altitudes, it tended to increase with increasing altitude. This study suggests that montane tropical forest soils consistently contain larger amounts of C compared to lowland tropical forests, and that conversion of forest to grasslands at higher altitudes might lead to larger soil C losses than previously expected.
•576 soil samples collected over 3000m elevation range in Papua New Guinea.•Soil carbon stocks increase 5.1kgC/m2 per 1000m in altitude.•Grassland soils contain less C than forst soils after bulk density correction.
Abstract
In recent years, increased awareness of the potential interactions between rising atmospheric
CO
2
concentrations (
CO
2
) and temperature has illustrated the importance of multifactorial ...ecosystem manipulation experiments for validating Earth System models. To address the urgent need for increased understanding of responses in multifactorial experiments, this article synthesizes how ecosystem productivity and soil processes respond to combined warming and
CO
2
manipulation, and compares it with those obtained in single factor
CO
2
and temperature manipulation experiments. Across all combined elevated
CO
2
and warming experiments, biomass production and soil respiration were typically enhanced. Responses to the combined treatment were more similar to those in the
CO
2
‐only treatment than to those in the warming‐only treatment. In contrast to warming‐only experiments, both the combined and the
CO
2
‐only treatments elicited larger stimulation of fine root biomass than of aboveground biomass, consistently stimulated soil respiration, and decreased foliar nitrogen (N) concentration. Nonetheless, mineral N availability declined less in the combined treatment than in the
CO
2
‐only treatment, possibly due to the warming‐induced acceleration of decomposition, implying that progressive nitrogen limitation (
PNL
) may not occur as commonly as anticipated from single factor
CO
2
treatment studies. Responses of total plant biomass, especially of aboveground biomass, revealed antagonistic interactions between elevated
CO
2
and warming, i.e. the response to the combined treatment was usually less‐than‐additive. This implies that productivity projections might be overestimated when models are parameterized based on single factor responses. Our results highlight the need for more (and especially more long‐term) multifactor manipulation experiments. Because single factor
CO
2
responses often dominated over warming responses in the combined treatments, our results also suggest that projected responses to future global warming in Earth System models should not be parameterized using single factor warming experiments.
To assess long-term functional outcome and survival among patients with meningioma World Health Organization (WHO) grade I.
Retrospective analysis of 205 patients after resection of WHO grade I ...intracranial meningioma from 1985 through 2003. Expected age- and sex-specific survival was calculated by applying Dutch life-table statistics to each patient for the individual duration of follow-up. Long-term functional outcome was assessed using a mailed questionnaire to the general practitioner.
The mean duration of follow-up was 11.5 years. Survival at 5, 10, 15, and 20 years was 92%, 81%, 63%, and 53%, respectively, which is significantly lower than the expected survival (94%, 86%, 78%, and 66%, respectively). Survival was worse with higher age (P < .001). Survival among patients younger than 45 years and older than 65 years was comparable to the expected survival but significantly worse among patients aged 45-65 years. Analysis of the cause of death suggests an excess mortality associated with both brain tumor death and stroke (P = .07). Recurrence rates at 5, 10, and 15 years were 18%, 26%, and 32%, respectively. Higher Simpson grade (P < .001) and lower age (P = .02) were associated with a higher recurrence rate. In 29 patients (14%) receiving radiotherapy, the 5-year recurrence rate was 18% and the 5-year survival was only 58%. Long-term functioning (≥ 5 years after last treatment) could be assessed in 89 long-term survivors: 29 patients (33%) showed no deficits, and 60 (67%) showed at least 1 neurological symptom, of whom 24 (27%) were unable to perform normal daily activities.
Long-term survival in WHO grade I meningioma is challenged in patients more than 45 years of age. Excess mortality seems to be associated with both tumor recurrence and stroke. The majority of patients have long-term neurological problems.
•Multi-center trial testing two personalised radiotherapy dose-escalation strategies.•107 patients with stage II/III disease and a large primary tumour were randomised.•24 fractions escalated dose to ...the whole primary tumour or the PET-subvolume.•Freedom from local failure rates were high (1-year > 90 %) in both arms.•Unexpected increased rates of grade 5 events were seen in both arms.
We aimed to assess if radiation dose escalation to either the whole primary tumour, or to an 18F-FDG-PET defined subvolume within the primary tumour known to be at high risk of local relapse, could improve local control in patients with locally advanced non-small-cell lung cancer.
Patients with inoperable, stage II-III NSCLC were randomised (1:1) to receive dose-escalated radiotherapy to the whole primary tumour or a PET-defined subvolume, in 24 fractions.
The primary endpoint was freedom from local failure (FFLF), assessed by central review of CT-imaging. A phase II ‘pick-the-winner’ design (alpha = 0.05; beta = 0.80) was applied to detect a 15 % increase in FFLF at 1-year. ClinicalTrials.gov:NCT01024829.
150 patients were enrolled. 54 patients were randomised to the whole tumour group and 53 to the PET-subvolume group. The trial was closed early due to slow accrual. Median dose/fraction to the boosted volume was 3.30 Gy in the whole tumour group, and 3.50 Gy in the PET-subvolume group. The 1-year FFLF rate was 97 % (95 %CI 91–100) in whole tumour group, and 91 % (95 %CI 82–100) in the PET-subvolume group. Acute grade ≥ 3 adverse events occurred in 23 (43 %) and 20 (38 %) patients, and late grade ≥ 3 in 12 (22 %) and 17 (32 %), respectively. Grade 5 events occurred in 19 (18 %) patients in total, of which before disease progression in 4 (7 %) in the whole tumour group, and 5 (9 %) in the PET-subvolume group.
Both strategies met the primary objective to improve local control with 1-year rates. However, both strategies led to unexpected high rates of grade 5 toxicity. Dose differentiation, improved patient selection and better sparing of central structures are proposed to improve dose-escalation strategies.
•The acute and late toxicity rates of the randomized phase II trial investigating dose-escalation in inoperable stage II–III NSCLC are presented.•Toxicity rates of isotoxic integrated boost to either ...the entire primary tumour or redistributed to regions of high pre-treatment FDG-uptake within the primary tumour were investigated.•The toxicity rates did not exceed the predefined stopping rules.
The PET-boost randomized phase II trial (NCT01024829) investigated dose-escalation to the entire primary tumour or redistributed to regions of high pre-treatment FDG-uptake in inoperable non-small cell lung cancer (NSCLC) patients. We present a toxicity analysis of the 107 patients randomized in the study.
Patients with stage II–III NSCLC were treated with an isotoxic integrated boost of ≥72 Gy in 24 fractions, with/without chemotherapy and strict dose limits. Toxicity was scored until death according to the CTCAEv3.0.
77 (72%) patients were treated with concurrent chemoradiotherapy. Acute and late ≥G3 occurred in 41% and 25%. For concurrent (C) and sequential or radiotherapy alone (S), the most common acute ≥G3 toxicities were: dysphagia in 14.3% (C) and 3.3% (S), dyspnoea in 2.6% (C) and 6.7% (S), pneumonitis in 0% (C) and 6.7% (S), cardiac toxicity in 6.5% (C) and 3.3% (S). Seventeen patients died of which in 13 patients a possible relation to treatment could not be excluded. In 10 of these 13 patients progressive disease was scored. Fatal pulmonary haemorrhages and oesophageal fistulae were observed in 9 patients.
Personalized dose-escalation in inoperable NSCLC patients results in higher acute and late toxicity compared to conventional chemoradiotherapy. The toxicity, however, was within the boundaries of the pre-defined stopping rules.
Researchers are increasingly using routine clinical data for care evaluations and feedback to patients and clinicians. The quality of these evaluations depends on the quality and completeness of the ...input data.
We assessed the performance of an electronic health record (EHR)-based data mining algorithm, using the example of the smoking status in a cardiovascular population. As a reference standard, we used the questionnaire from the Utrecht Cardiovascular Cohort (UCC). To assess diagnostic accuracy, we calculated sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV).
We analyzed 1,661 patients included in the UCC to January 18, 2019. Of those, 14% (n = 238) had missing information on smoking status in the UCC questionnaire. Data mining provided information on smoking status in 99% of the 1,661 participants. Diagnostic accuracy for current smoking was sensitivity 88%, specificity 92%, NPV 98%, and PPV 63%. From false positives, 85% reported they had quit smoking at the time of the UCC.
Data mining showed great potential in retrieving information on smoking (a near complete yield). Its diagnostic performance is good for negative smoking statuses. The implications of misclassification with data mining are dependent on the application of the data.
PDF
